Concentrator.



A. 0. GATES.

CONCENTRATORQ APPLICATION FILED JULY 25.1913.

1,213,348, Patented Jan. 23, 1917.

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A. O. GATES.

CONCENTRATOR.

APPLICATION FILED JULY 25.1913.

Patented Jan. 23, 1917.

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GFFIC ARTHUR O. GATES, OF LA FAYETTE, INDIANA.

CONCENTRATOR.

Application filed July 25, 1913.

To all whom it may concern:

Be it known that I, ARTHUR O. GATES, a citizen of the United States of America, residing at La Fayette, in the county of Tippecanoe and State of Indiana, have invented a new and useful Concentrator, of which the following is a specification, reference being had to the accompanying drawings, illustrating same.

My invention relates to concentrators, or, in other words, to concentrating machines, etc., used for separating one or more materials from other materials, such as, for example, a heavy mineral, or a combination of mlnerals, from lighter (usually waste) material. My invention, in its various forms, may, however, be used for a great variety of purposes and for effecting a great variety of separations, in connection with solids,

liquids, and even gases.

One object of my invention is, to provide an improved concentrator, or concentrating machine, which utilizes for the purposes of separation the force of gravity and the outward force of rotation or in other words a centrifugal force, and a combination of these forces the resultant of which varies both in direction and amount for different portions of the rotation or different angular positions, and which resultant is made to vary as desired so as to bring about the desired results.

Another object of my invention is to provide in a concentrating machine a multiplicity or large number of separating surfaces disposed about a rotating axis, or in the form of a wheel, whereby a very large area of separating surface is condensed into a very small space.

Still another object of my invention is to provide in such a concentrating machine a suitable shaping of the separating surfaces whereby the resultant forces on the materials at the various angular positions of the rotation may be utilized to cause the proper movements of the materials across the separating surfaces.

Still another object of the invention is to provide a machine wherein reliable methods of separation may be carried out under more advantageous conditions.

Still another object of the invention is to provide means in a slime concentrator whereby the pools of slime may be made to come in contact with the separating plates both above and below so as to greatly reduce Specification of Letters Patent.

Patented Jan. 23, 1917.

Serial No. 781,162.

or eliminate the objectionable effect of surface tension which tends to hold some of the heavy minerals at the surface and thereby let them be washed off with the lighter rejections. I

Still another object of the invention is to provide a centrifugal concentrator which may be run efficiently at slow speeds, thus greatly reducing the required operating power and also the wear andtear on the machine.

Still further objects of the invention are to provide simplicity, cheapness of manufacture, and high efiiciency in such machines, and a great reduction in size over other machines for the same output.

Still other objects will be apparent from the following specification.

In the accompanying drawings illustrating the preferred forms of my invention, Figure l is a transverse cross-section of one form of my machine, taken on plane a: w of Fig. 2, also showing certain diagrammatic representations Fig. 2 is a longitudinal or axial cross-section of the machine of Fig. 1, taken on plane y 3/ of Fig. l, with portions shown in elevation and the driving mechanism removed; and Fig. 3 is a transverse cross-section of a modified form of my invention, taken the same as Fig. 1.

Like characters refer to like parts in the several figures.

My machine is of the general type of separating machines in which thin layers of the material to be separated are spread out by mechanical means over the separating surfaces, the actual separation taking place practically in contact with the surface of the separators, be it a screening, filtering, stratifying, or skimming process. In all such machines the greater the area over which the material to be separated may be spread, the greater the capacity of the machine for efficient separation.

' In my present invention I have found means whereby a very great amount of area to be used for separating purposes may be contained within a very small space, and by utilizing the varying intensity and direction of the acting forces the separations may be carried on in a very efficient manner, with a very large output for the machine and with a very great reduction in the usual amount of mechanism required.

The varying intensity and direction of in connection therewith;

the forces utilized in making the separations I obtain by revolving the separating surfaces about a horizontal or inclined axis, the forces being gravity, always acting down ward, and a centrifugal force, always acting radially.

While the force of gravity is always the same on a certain mass in a certain locality, and always downward, and while for any given speed the centrifugal force on a certain particle in a revolving mass is constant and always radial, the resultant force acting on a particle of the said mass is a variable quantity, both in amount and direction, depending upon the angular position of the particle under consideration, and is, furthermore, no longer radial. This I will now explain more in detail by reference to Fig. 1 of the drawings, as follows: Let C be a particle rotating about a horizontal axis A in the direction of arrow G. Let the forces acting on the particle C be represented in direction and amount by the line C D for gravity and the line C E (which is preferably taken equal to the radius A C) forthe centrifugal force. The resultant of these two forces may then be represented in direction and amount by the line C F, according to the well-known parallelogram of forces. Now, if we transfer the point C to the point B in a vertical line through the axis A, so that A B G D, then the line B C will represent the resultant force acting on the particle C. B may then be considered to be a fixed point, because the line A B represents the force of gravity acting on the particle C, which force is always the same in amount and always vertical. Now as the particle C rotates about A, the resultant force B C will rotate about B and will be least in amount when the particle C is at its highest position and greatest in amount when the particle C is at its lowest position, the resultant B C being radial to the motion of the particle C only when the latter is in its highest and lowest positions. It can therefore be seen that the resultant force acting on the particle C varies both in direction and amount as the particle C revolves about the axis A.

As the force of gravity A B is constant in both direction and amount, the resultant force B C acting on a particle maybe variedfor any angular position of the particle only by varying the centrifugal force C E or A C acting on the particle, which is accomplished by varying the speed of rotation. Should the centrifugal force A C be less than the force of gravity A B, the particle C carried on the inside of a revolving surface would be free to fall at its highest position, and would thus no longer be under the influence of the centrifugal force at this point. On the other hand, if the speed were increased so that the centrifugal force A C would be many times the force of gravity A B, the

effect of the force of gravity would be so small that the resultant B C would practically coincide with the centrifugal force A C, in which case the effect of the force of gravity would be insignificant. Thus, in order to properly utilize the combination of the two forces of gravity and rotation in my concentrator to produce the desired results, I preferably run my machine at such a speed that the ratio of the force ofgravity A B to the centrifugal force A C is between the ratios 1 to 1 and 1 to 5, or thereabout, for ordinary uses, although in various applications of the machine I may vary this ratio considerably.

Ordinary revolving screens (tronnnels) run at speeds such that the ratio of the centrifugal force to the force of gravity is less than 1 to 1, and they would not be operative at 1 to 1 or a greater ratio. Centrifugal force is not considered advantageous in these machines.

In centrifugal separating machines such as a cream separators and such separators as have been tried for concentration in connection with mining, the ratio of the centrifugal force to the force of gravity is from 100 to 1, to over 1000 to 1.

In a'rotating mass turning about a horizontal axis, there are points of equal pressure, or, in other words, .particles on which the resultant forces are the same for a cerequal pressure when revolved, which surface,

in the case of a liquid being revolved about a horizontal axis A, will be in the form of the arc of a circle, of which B is the center. Therefore, the circles about the point B may be regarded as liquid-level lines. These liquid-level lines, such as H, I, J, K, L, M, N and O, of Fig. 1 of the drawings, correspond to horizontal surfaces in the case of gravity machines. It can therefore be seen that by arranging separating surfaces with regard to these liquid-level lines, surfaces upon which separations take place under the influence of single forces such as gravity or gaseous pressure, and also the separations themselves, may be simulated. Such surfaces, as for instance the surfaces 1, 2, 3, 4;, 5, 6, 7, 8, 9, 10, 11, 12, etc., of Figs. 1 and 3, are so shaped that they may be placed very close together about A as a center, in the form of a wheel, thus providing a very great amount of separating surface in a very small space.

In the drawings, illustrating the preferred forms of my invention and embodying the essential features thereof, these separating surfaces 1 to 12 inclusive, and intermediate surfaces in Fig. 3, are shown as curved sheets or plates of the proper material, held between the ring-disks 13 and 14 by some suitable means, such as bolts, rivets, etc. To the disk 14 is attached a spider 15 having a hub 17 thereon which is preferably keyed to a shaft 18, the latter being supported by and running in suitable bearings, one of which is shown at 19. Any suitable driving mechanism may cooperate with the shaft 18 for rotating the separator 20 as a whole, as desired. Projecting into the central opening of the separator 20 is a pipe 21 for spraying water onto the separating surfaces or plates at the proper time as they revolve, and also a pipe 22 for spraying the pulp or material to be separated onto the separating surfaces or plates at the proper time as they revolve.

31 is a rejection spout which conveys the rejected material out of the machine as at 32. Other details of construction of the machine or separator may be supplied to suit the requirements.

In my separator the relation between the liquid-level lines H, I, J, K, L, M, N and O, and the separating surfaces 1 to 12 inclusive, and intermediate surfaces in Fig. 3, is such that the effect of either a gradual or rapid tilting of a horizontal gravity separating surface may be obtained, and this without any additional mechanism. For instance, when a separating surface reaches the position 10, the liquid-level lines are practically at right angles to the separating surface and a rapid flow of the material then takes place across the separating surface and off the outer edge thereof, as will be more fully explained hereinbelow.

The angles between the liquid-level lines and the curved separating surfaces of my machine, correspond to the angles of inclination of the surfaces of gravity machines, and the effect in my machine is the same as if the surface of the gravity machine were flexible and were tilted with a wave motion during a cycle of its operation corresponding to one revolution of my machine. In other words, the effect of a revolution of my separating surfaces about a horizontal axis is analogous to the movement of a flexible surface which is tilted back and forth with a wave motion, the crest of the wave making its full travel back and forth in a period corresponding to one revolution of a separating surface of my machine. In such a gravity machine the movement of the fluid across the separating surface would be controlled by the shape and position of the flexible surface and gravity, while in my machine the movement of the fluid across the separating surface is controlled by the shape of the separating surface and the resultant of gravity and the centrifugal force. In my machine I utilize this latter control of the material to obtain either a rapid or slow movement thereof across the separating surfaces in planes substantially at right-angles to the axis of rotation, or to obtain periods of movement and periods of rest, as conditions may require. This movement of the material may be entirely in one direction (outward), or back and forth across the separating surfaces, according to the shape of the, surfaces and the speed of the machine, both of which may be varied as desired.

In my machine the force affecting the separation is from two to six times that utilized in a gravity machine, thus giving a higher velocity against the separating surfaces and making separations more rapid than in gravity machines. The pulp is fed onto the separating surfaces of my machine at the lower portion of their revolution, where the consequently separation begins at the most rapid rate. Utilizing the principles set forth above, 1n combination with the multiplicity of separating surfaces closely spaced from each other in a revolving wheel and the result ant of gravity and the centrifugal force for causing the separations, it is my intention to also incorporate into such separating machines such other principles and constructions as are common to the art, if desired.

The separators illustrated in the drawings are preferably slime concentrators, the construction of which is set forth above. These machines are designed for separating minerals in a finely divided state, those of higher specific gravity from those or other materials of lower specific gravity, the combined materials being initially suspended in a liquid, such as water, in the form of a pulp, when fed into the machine. The separator 20 preferably revolves at a uniform speed, in the direction of arrow P. The material or pulp to be separated is fed onto the separating plates 1 to 12 inclusive, and intermediate plates in Fig. 3, as they revolve in the direction of arrow P, preferably when these plates are in the positions 2, 3, 4E and intermediate positions, by being sprayed onto the plates through closed-ended pipe 22. The separating plates in these positions catch the material on the concave faces thereof, upon which it spreads out, flowing toward the outer edges of the plates in accordance with the liquid-level lines L, M, N and 0, above described, which at the positions 2, 3 and 4 of the plates are such as to cause this flow of the material, as can be readily seen from Fig. l of the drawings. These liquid-level lines L, M, N and 0 show the positions which liquids tend to assume while passing these points of the rotation, if supported, but as the liquids are unsupported on the side in the direction of the rotation, at these points, they will conseresultant force is greatest, and

holes 23 in the positions.

quently flow toward this unsupported side, which is toward the outer edges of the separating plates. This first flow of the liquid or pulp on the separating surfaces requires an appreciable time, and in this time the plates are carried by their rotation into the successive positions 3, l, 5, 6 and intermediate positions. In these latter positions the liquid-level lines N, M, L and K become more nearly parallel with the separating surfaces and cut the latter at two points, so that the liquids at these portions of the rotation are supported by the separating plates so as to form pools at 2a, 25, 2-6 and 27 thereon. Thus it can be seen that in consequence of the rotation the feed can be regulated so that none of the liquid or pulp flows ofi of the outer edges of the separating plates at these positions. These pools of the pulp may be determined in size and depth by the shape of the separating plates and the regulation of the quantity of the feed. Now, as the separator revolves still further, the pools 524, 25, :26 and 27 of the pulp work gradually toward the inner edges of the separating plates, in accordance with the liquid-level lines, at the same time the heavier minerals clinging to the surfaces of the plates, and when the plates reach the positions 7, 8 and intermediate positions, the lighter or top portions of the pools flow off of the inner edges of the separating plates as at 28, and 29, into the rejection spout 31 which conveys the rejections out of one side of the machine as shown at Now, when the separating plates reach the positions 9, 10, or l0, l1, and intermediate positions, in their rotation, they are sprayed with water from the pipe 21 as at 33 and 3a, which washes the heavier minerals or concentrates toward and off of the outer edges of the separating plates as at 35 and 36, when the plates are in the positions 10, 11 and intermediate positions, into a suitable receptacle, not shown, thus cleaning the plates of all of the material and preparing them for a new charge when they again reach the positions 2, 3, at and intermediate In accordance with the liquidlevel lines at the positions 10 and 11 of the separating plates, which are here practically perpendicular to the separating plates, the wash of the heavier minerals runs off of the outeredges of the plates at a high velocity, thus scouring the plates thoroughly of the heavier minerals which previously clung thereto. Thus it will be seen that by the process above set forth, the separation of the heavier minerals from the pulp is accomplished eiiiciently, rapidly, and in a very simple manner.

By increasing the speed of the machines illustrated the center B of the liquid-level circles is lowered toward the axis A of the machine, and by decreasing the speed the center 13 is raised, so that by changing the speed the relation of the liquid-level circles to the separating surfaces is changed, and

consequently a variation in the operating conditions is thus obtained.

One great ad antage of my machine is the slow speed at which it will operate. For instance, a twelve-inch wheel will operate successfully at a speed of about 100 R. P. M., and a tenfoot wheel will operate successfully at from 30 to 40 R. P. M. Thus in my machine I effect a great saving in power and also in wear and tear on the machine.

If desired, I may place the separating plates of the slime separator, close enough together so that the pools of slime come in contact with said plates both above and below, as shown in Fig. 3, whereby the usual surface tension which tends to hold some of the finely divided heavy minerals at the surface of the pools and let them be washed off with the lighter rejections, is eliminated.

I do not wish to limit this invention to the particular details herein set forth, nor to the particular construction shown, as a great variety of modifications thereof may be made or utilized without departing from the scope of the appended claims.

lVhat I claim as my invention is:

1. A concentrator of the character set forth having a plurality of separating surfaces arranged in the form of a hollow wheel and to revolve about a substantially horizontal axis, a spray pipe entering the hollow portion of the wheel forspraying the material to be separated onto the separatin surfaces at the lower portion of their revolution, the said separating surfaces being curved so that the varying resultant force of gravity and the centrifugal force on the material causes a reciprocating flow of the said material across the separating surfaces during a revolution thereof whereby some of the material is discharged from the inner edges of the said surfaces at a certain part of the revolution and other portions of the material are retained on the said surfaces, a trough entering the hollow portion of the said wheel for catching the said discharged portions of the material and carrying same out of the wheel, and a second spray pipe entering the hollow portion of the wheel for spraying water onto the separating surfaces at the higher portion of their revolution to wash the said portions ,of the material which are retained on the separating surfaces, off of the outer edges thereof at a certain part of the revolution.

2'. A concentrator of the character set forth having a plurality of separating surfaces arranged to revolve about a substantially horizontal aXis, means for feeding curved outwardly from the said axis and in the direction of rotation in a manner such that the varying resultant force of gravity and centrifugal force on the said material causes a reciprocating flow of the said material across the separating surfaces during a revolution thereof whereby some of the material is discharged from the said surfaces at a certain part of the revolution, other portions of the material being retained on the said surfaces, and means for causing a discharge of the latter said portions of the material from the separating surfaces at a certain part of the revolution.

3. A concentrator having a plurality of separating surfaces arranged in the form of a wheel to revolve about a substantially horizontal axis, means for feeding the material to be separated onto the said surfaces in their downwardly and outwardly sloping positions, the said surfaces being curved outwardly from the said axis and in the direction of rotation in a manner such that the varying resultant force of gravity and cen trifugal force on the material causes a reciprocating flow of the material across the separating surfaces during a revolution thereof whereby certain portions of the material are separated from, other portions thereof and discharged from the said separating surfaces at a certain part of the revolution, and means for washing ofi" the remainder of the said material from the separating surfaces at a certain part of the revolution.

A. A concentrator having a plurality of separating surfaces arranged in the form of a wheel to revolve about a substantially horizontal axis, and means for feeding the material to be separated onto the said surfaces in their downwardly and outwardly sloping positions, the said surfaces being curved outwardly from the said axis and in the direction of rotation in a manner such that the varying resultant force of gravity and centrifugal force on the material causes a reciprocating flow of the material across the separating surfaces whereby certain portions of the material are separated from other portions thereof and discharged from the separating surfaces at a certain part of the revolution.

5. A concentrator having a plurality of revolving separating surfaces arranged in the form of a wheel and curved outwardly from the axis of rotation and in the direction of rotation in a manner such that the varying resultant force of gravity and centrifugal force causes a reciprocating move-- ment of the material to be separated across the separating surfaces during a revolution thereof, and means for delivering material to the separating surfaces in their downwardly and outwardly sloping positions.

6. A concentrator having a plurality of revolving separating surfaces arranged in the form of a wheel and curved outwardly from the axis of rotation and in the direction of rotation in a manner so as to utilize a resultant force varying both in direction and amount for different angular positions thereof for causing a reciprocating flow of material across such surfaces to effect separation of different parts of said material, and means for delivering material to the separating surfaces in their downwardly and outwardly sloping positions.

7. 'A concentrator having a revolving separating surface curved outwardly from the axis of rotation and in the direction of rotation in a manner so as to utilize a resultant force varying both in direction and amount for different angular positions thereof for causing a reciprocating flow of material across such surface to effect separation of different parts of said material, and means for delivering material to the separating surface in its downwardly and outwardly sloping position.

8. A concentrator having a plurality of revolving separating surfaces curved outwardly from the axis of rotation and in the direction of rotation in a manner such that the pools of liquid fed thereon reciprocate thereacross, due to the resultant of gravity and centrifugal force, as the separating surfaces revolve, and means for delivering material to the separating surfaces in their downwardly and outwardly sloping positions.

9. A concentrator having a plurality of revolving separating surfaces curved, outwardly from the axis of rotation and in the direction of rotation in a manner such that the liquid levels in relation thereto cause a reciprocating movement of material thereacross during revolution, and means for delivering material to the separating surfaces in their downwardly and outwardly sloping positions.

10. A concentrator having a plurality of revolving separating plates similarly arranged around an axis and curved in the direction of rotation, the said plates being spaced close enough to each other whereby pools of slime th-erebetween come in contact vwith the plates both above and below the pools to eliminate the usual surface tension of the latter.

11. A concentrator having a plurality of revolving separating plates curved in the direction of rotation so as to properly control the material fed therebetween, the said plates being spaced close enough to each other whereby the material therebetween comes in contact with both of the plates adjacent thereto to eliminate the usual surface tension of the material.

12. A concentrator having a plurality of revolving separating plates arranged in the form of a Wheel and curved so that the varying resultant force of gravitv and centrifugal force causes a reciprocating movement of the material to be separated across the separating surfaces during a revolution thereof the said plates being close enough to each other whereby the material therebetween comes in contact with both of the said plates adjacent thereto to eliminate the usual surface tension of the material.

13. A concentrator having a revolving separating surface curved outwardly from the axis of rotation and in the direction of rotation in a manner such that the varying 15 resultant force of gravity and centrifugal force causes a reciprocating movement of the material to be separated across the separating surface during a revolution thereof, and means for delivering material to the 20 separating surface in its downwardly and outwardly sloping position.

As inventor of the foregoing I hereunto subscribe my name, this 15 day of July, 1913.

ARTHUR O. GATES. Witnesses:

GEORGIANA E. GATES, MINNIE W. ELLIOTT.

Copies of this patent may be obtained for live cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

